1. Technical Field
Some example embodiments relate generally to semiconductor devices, and more particularly, to methods of measuring and controlling an inner temperature of a chamber included in a test handler in real-time.
2. Description of the Related Art
In general, semiconductor devices require a test process and a test handler is used to simultaneously test a plurality of semiconductor devices under severe conditions such as higher temperatures beyond room temperature. For example, 256 or 512 semiconductor memory devices may be mounted and disposed in a chamber of the test handler and the inner space of the chamber may be filled with nitrogen gas. Using a heater and a fan included in the chamber, the inner air of the chamber may be set to a given (or, alternatively predetermined) test temperature. The inner temperature of the chamber may be monitored using temperature sensors to control the heater and the fan so that the inner temperature may be maintained at the set temperature.
Even though the performance of the heater directly affects the temperature distribution in the chamber, it is difficult to control the temperature distribution exactly because of the heat caused by the respective semiconductor memory devices under test. To enhance yield and reliability of products through the test, the operational temperature of the respective semiconductor memory device under test needs to be maintained near the given (or, alternatively predetermined) target temperature. It is most desirable to provide a temperature control system capable of independently controlling the operational temperature of each device under test but such temperature control system increases testing costs as the number of the devices tested simultaneously increases.